“Fast food consumption was related to fast food availability among low-income respondents, particularly within 1 to 2.99 km of home among men,” the study found.

The link between junk food consumption and proximity to home was particularly strong for low income men, “who may be less likely to own a car, thereby limiting mobility and enhancing reliance on the immediate neighbourhood area.”

“Greater supermarket availability was generally unrelated to diet quality and fruit and vegetable intake, and relationships between grocery store availability and diet outcomes were mixed.”

The authors said their study supported a push by some U.S. policymakers to tackle ‘food deserts’ – neighbourhoods where healthy food is hard to find – by putting zoning restrictions on fast food restaurants within 3 km of low-income households.

However, encouraging a nutritious diet will require more than urban planning changes, they said, as the study showed living close to shops stocking healthy food was not enough to promote better food choices.

Professor John Coveney, a specialist in public food policy at the Flinders University School of Medicine, said the U.S. study was interesting but that its lessons did not necessarily apply in Australia.

“Here, it makes little difference to where people live in relation to the supermarkets and what they buy because they use their car to get what they want and to get the best deal,” said Professor Coveney.

“Our studies have shown that, here, even low income people have access to private transport. People are happy to travel distances to get what they want or like.”